Combat training systems existing today are generally built-up based on a central station communicating with a number of players such as soldiers, laser based weapon simulation systems, etc. The players are arranged to report to the central station registered events such as fire/trigger, detonation, hit, far miss, near miss and side effects together with time information and information about the location of the player.
It has become more and more important to train soldiers for battles not only in conventional training terrain but also in urban terrain. However, in urban terrain conventional position location systems such as GPS do not function properly, as the GPS-signals do not reach indoors and other enclosed spaces. Therefore, it has not been possible to directly apply the combat training systems to training in urban terrain without first solving the problem of position determination in enclosed spaces, such as in buildings.
U.S. Pat. No. 5,917,425 describes a system for determining the location and the identity of a device or person in an enclosure. The system comprises a plurality of stationary infrared transmitters distributed in various zones within the enclosure and a plurality of portable transceivers, each being associated with a dedicated person or device. Each of the transmitters includes means for generating an infrared location code signal representative of the location of the associated transmitter within the enclosure. Each of the portable transceivers is formed from an infrared receiver responsive to detect infrared location code signals from stationary infrared transmitters, means for generating a PIN signal representative of the person or device with which the portable transceiver is associated, and an RF transmitter to generate bursts of an RF output signal representative of the PIN code and the detected location code for detection by a remote RF receiver and use at a central station.
WO 97/35208 concerns a method and device for determining the position of moving objects, in particular moving participants in battle practice. Optoelectronic transmitters are disposed in sections/rooms/shelters in the battle practice field, the optoelectronic transmitters continuously transmitting data concerning at least the transmitter position. If a moving object enters the optoelectronic transmitter reception range, a receiver of the moving object receives the data concerning the transmitter position and the received data is transmitted via a radio data transmission system to a battle control centre. The method described enables the exact position of the moving objects and participants in the battle practice to be determined even when they are located in rooms or on sites which makes it impossible to determine positions using GPS signals.
U.S. Pat. No. 6,579,097 describes a method of training players in an urban environment. The method comprises the steps of equipping a plurality of players with optical detectors, SAT-equipped small arms weapons and player units; installing a locator in a combat area and causing the players to enter the combat area. The locator transmits infrared energy, the infrared energy having a location code located therein. The optical detectors of at least one of the players that has entered the combat area receives the infrared energy transmitted from the locator, and the location code in the received infrared energy is logged in the player unit of a player that has received the infrared energy.
Using the above mentioned solutions, it is possible to provide position determination also in enclosed spaces, such as in buildings. In a combat training system based on these position determination solutions for urban training, the central unit has means for relating every received location code to a specific space or a specific room in a specific building, for example graphically. However, it is not possible to apply the above mentioned positioning determination solutions in communication with units which are not provided with the above mentioned means. Especially, with the above mentioned position determination methods, the player units themselves do not know their positions.